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First ever long-term GM feeding study on pigs

August 2013

“ ... more than 150 scientific
studies have been done on animals fed biotech crops and to date,
there is no scientific evidence of any detrimental impact”
(biotech representative, CropLife International).

With a bit of cherry-picking of what
constitutes appropriate scientific evidence this may be true.
However, it's easy to see why no 'detrimental impact' has emerged.
The 'scientific studies' has been largely based on animal models with
little relevance to humans, on diets restricted to single GMOs, on
very short time-scales, and on superficial data relevant only to
commercial livestock production.

When a team of Australian and American
scientists, led by Dr. Judy Carman, carried out an experiment which
avoided the above short-comings, it raised concerns.

Carman's study used pigs (whose
physiology is close to humans) and a real-life situation. The
animals lived for their normal commercial life-span of 22-23 weeks
when adulthood is attained. They were fed a routine mixture of GM
corn and GM soya in feed closely controlled for texture and
nutritional quality. Extensive data on growth, mortality, feed
intake, blood parameters and organ changes were collected.

Significantly, the results on body
weight and standard blood biochemistry, which the biotech industry
have persuaded regulators are sufficient endpoints in health
assessments, were entirely normal. However, a 25% increase in
uterine weight in GM-fed pigs was suggestive of endocrine disruption,
and a two- to four-fold higher incidence of severe stomach
inflammation indicated chronic digestive system problems.

These are very important findings in
view of the background to this investigation: the anecdotal evidence
put forward by pig farmers.

An Iowa-based crop and livestock adviser and farmer reported

“For as long as GM crops have been in
the feed supply, we have seen increasing digestive and reproductive
problems in animals ... In my experience, farmers have found
increased production costs and escalating antibiotic use when feeding
GM crops. In some operations, the livestock death loss is high, and
there are unexplained problems including spontaneous abortions,
deformities of new-born animals, and an overall listlessness and lack
of contentment in the animals. In some cases, animals eating GM
crops are aggressive. This is not surprising, given the scale of
stomach irritation and inflammation now documented.”

A previous, very short-term (31-day)
experiment on male piglets fed a diet of MON810 'Bt' insecticidal
maize recorded an increase in 'goblet cells' in the gut lining (see
PIG FEEDING STUDY NOT REASSURING - February 2012). Goblet cells secrete a
protective mucus layer. An increase in their numbers is a first
response to the presence of harmful materials passing through.

It is these sick animals which become
our food.

Predictably, the usual furore of
criticisms erupted in response to the hint of GM-bad-news.

Mark Lynas, self-styled GM champion
(see WHEN NON-NEWS IS BAD NEWS - April 2013) cherry-picked a few
figures from Carman's data and tried to allege they were
statistically significant (they weren't) and that they were being
deliberately ignored. As Carman pointed out, only statistically
significant findings were discussed in the paper “because this is
the scientifically credible approach”. Lynas' claim that
his (non-professional) reading of the scientific literature on
climate change,
has given him what it takes to understand GM technology is exposed
for what it is.

Monsanto
leapt (before it looked) to suggest that the uterine
weight increases were simply caused by the pigs coming into estrus.
In Carman's words since “everything except for the GM aspect of
diet” was “randomised out” by the study design, the uterine
changes were shown to be due to the diet. She continued if
“Monsanto is actually suggesting that the GM diet caused a
difference in the rates of estrus in the pigs. This is a hypothesis
that is both interesting and worrying for health and should be
followed-up.”

OUR COMMENT

The most important criticism of Carman's pig study, because of its wider implications, is that the use of a routine commercial feed, which includes a cocktail of agri-chemicals, GM proteins and who-knows what else, “muddies the water” too much to interpret the results.

The current situation which has evolved with full regulatory approval is that non-GM parent crops for a valid scientific comparison of GM and non-GM are simply not available. Add to this that the agri-chemicals used on GM and non-GM crops will be different, and that pure non-GM seed can no longer be obtained. More seriously, in the case of the newer varieties such as SmartStax maize which looks set to gain approval in the EU and has multiple artificial genes stacked by cross-breeding, a valid parent replica simply can't be created. Carman's real-life experiment is the best science now possible.

Regulators are using the muddied situation they have encouraged as an excuse to deny us safety testing. However, as Carman pointed out, because the waters are muddied, any harmful effects will have to be greater to show statistical significance: this makes her finding even more ominous.

It's time our regulators got their act together and specified valid protocols, acceptable controls and up-to-date tests for routine use. Ask them to do this before they ask any pigs, or you, to eat GM.

Welcome to GM-free Scotland

About us

Formerly known as the Scottish Consumers Association for Natural Food, Pro-natural Food Scotland was formed in 1996 by a group of concerned people in Glasgow, Scotland. We are funded entirely by donation and run by volunteers. We network with, and support, all like-minded groups and individuals. Our objective is to empower by raising awareness.